7. Project Summary/Abstract Only 43% of children in the U.S., ages 6-11 yrs., meet current moderate-to-vigorous physical activity (MVPA, 4-6 METs, 300 min/wk.) guidelines. The CDC, in collaboration with the Society for Health and Physical Educators, recommends Comprehensive School Physical Activity Programs (CSPAP), which target physical education (PE), PA before, during and after school, staff, and family and community involvement to increase moderate-to-vigorous physical activity (MVPA) in children. However, the magnitude of the effect of the CSPAP approach on MVPA is small to moderate at best. The lack of effectiveness may be due in part to the cost and difficulty of implementing this complex strategy, and the trend towards decreasing time for PE, which is a cornerstone of the CSPAP approach. To satisfy MVPA requirements of School Wellness Policies, schools have incorporated classroom MVPA, in the form of activity breaks, or MVPA integrated into academic lessons. However, survey data indicates only ~22% of elementary schools in the U.S. use activity breaks with ~10 min/day of MVPA. We completed two, 3 academic-yr. cluster randomized trials (DK61489, DK85317) which involved increasing MVPA in the classroom we called ?Physical Activity Across the Curriculum? (PAAC). Elementary school classroom teachers were trained to deliver two, 10-min academic lessons incorporating MVPA each day over 3 yrs. to students in grades 2 and 3 at baseline. Across 3-yrs. teachers in PAAC schools delivered ~60 min/wk. (12 min/day) of MVPA. Although short of our MVPA goal (20 min/d), the 12 min/day achieved represents 40% of the recommended 30 min of MVPA during the school day, and is ? MVPA delivered in 3 typical PE classes/wk. Thus, the PAAC approach has demonstrated the potential for substantially increased in-school MVPA elementary schools. Teacher reluctance to devote additional time to develop and integrate physically active lessons into their curriculum was the overwhelming barrier to meeting the MVPA goal. Therefore, to reduce barriers to delivery of classroom MVPA we developed a series of pre- recorded activity breaks (PAAC-R, ~10 min MVPA), conducted by an experienced physical educator, that can be delivered remotely to classrooms via the internet and displayed on a flat screen monitor. Results from a recently completed 4-wk pilot trial in 3 elementary school classrooms (grades 2,3,4) using these remotely delivered activity breaks indicated 10 min of MVPA (accelerometer) was achieved in 100% of sessions in grades 2 and 3, and 97.5% of sessions in grade 4. The proposed 3 academic yr. cluster randomized trial (2 yrs. active intervention, 1 yr. follow-up) will compare the effectiveness and sustainability of remotely delivered (PAAC-R) and classroom teacher delivered (PAAC-T) activity breaks for increasing classroom MVPA in elementary school students in grades 2 and 3 at baseline who will progress to grades 4-5.